Empty user agent string on T46G

[stefan@nunetworx.com]

When auto provisioning our phones we rely on the user agent string supplied by the phone in the request to the auto_provision.server.url to identify itself, i.e. "Yealink SIP-T46G 28.71.0.70 MAC-Address".

However, on our brand new T46G, firmware 28.71.0.70, it appears to send an empty user agent string by default.

If I export the configuration to config.bin, I can see a section that reads:
[ HttpServer ]
bEnable = 1
nPort = 80
strUserAgent =
strHttpVersion = 1.0
strUseragentDynm = SIP-T46G 28.71.0.70

And if I modify the strUserAgent string and import the configuration again, the phone does indeed supply the user agent string to the auto provision server.

Is there anything we can put in our auto provisioning configurations to get the phone to send a user agent string?